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Discussion :: Problems on H.C.F and L.C.M

  1.  

    What will be the least number which when doubled will be exactly divisible by 12, 18, 21 and 30 ?

  2. A.

    196

    B.

    630

    C.

    1260

    D.

    2520

    View Answer

    Workspace

    Answer : Option B

    Explanation :

    L.C.M. of 12, 18, 21 30                 2 | 12  -  18  -  21  -  30
                                             ----------------------------
       = 2 x 3 x 2 x 3 x 7 x 5 = 1260.       3 |  6  -   9  -  21  -  15
                                             ----------------------------
       Required number = (1260 � 2)            |  2  -   3  -   7  -   5
    
                       = 630.


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